数据流目的，操作基本变量和String类型进行持久化操作
import java.io.*;

/**
 * @auto dh
 * @create 2020-04-24-17:34
 */
public class File006 {
    public static void main(String[] args) {
        DataOutputStream ds = null;
        DataInputStream di = null;
        try {
            ds = new DataOutputStream(new FileOutputStream("D:" + File.separator + "ac.txt"));
            di = new DataInputStream(new FileInputStream("D:" + File.separator + "ac.txt"));
            ds.writeUTF("张无忌");
            ds.write(24);
            String name=di.readUTF();
            int age=di.read();
            System.out.println("name: "+name);
            System.out.println("age: "+age);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (ds != null) {
                try {
                    ds.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if(di!=null){
                try {
                    di.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}